In an image compression method such as moving picture experts group (MPEG)-1, MPEG-2, and MPEG-4 H.264/MPEG-4 AVC (advanced video coding), an image is divided into blocks, each having a predetermined size, and residual data of each block is acquired by using an inter prediction or an intra prediction process. The residual data is compressed through processes such as transformation, quantization, scanning, run length coding, and entropy coding. During the entropy coding operation, a syntax element, for example, information about, for example, a transformation coefficient or a prediction mode, is entropy encoded, and a bit stream is output. A decoder parses the bit stream to extract syntax elements, and restores image based on the extracted syntax elements.